Cysteine variants of erythropoietin

Patent Number: 7,314,921

This patent covers the composition of matter for specific variants of erythropoietin, the renal secreted hormone responsible for generation of erythrocyte differentiation from bone marrow hematopoietic stem cells. Specifically, the patent covers variants of the erythropoietin molecule in which the amino acid cysteine is substituted for amino acids that are not essential for erythropoietin binding to its receptor. Unique locations for the cystein substitution are covered. These include substituting the cysteine in loop regions, ends of alpha helices, or at various glycosylation sites. These substitutions not only provide altered pharmacokinetics and biodistribution profile of erythropoietin, but may also theoretically be used to provide proprietary positions in the manufacture of erythropoietin since the core composition of matter patents have expired or are soon to expire.

This patent is also interesting since erythropoietin is involved on only in hematopoiesis but also protection from stroke. Actually peptides derived from erythropoietin have also been demonstrated to have neuroprotective properties.

View this patent on the USPTO website.